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<h2><a href="closure_goog_labs_observe_observer.js.html">observer.js</a></h2>

<pre class="prettyprint lang-js">
<a name="line1"></a>// Copyright 2012 The Closure Library Authors. All Rights Reserved.
<a name="line2"></a>//
<a name="line3"></a>// Licensed under the Apache License, Version 2.0 (the &quot;License&quot;);
<a name="line4"></a>// you may not use this file except in compliance with the License.
<a name="line5"></a>// You may obtain a copy of the License at
<a name="line6"></a>//
<a name="line7"></a>//      http://www.apache.org/licenses/LICENSE-2.0
<a name="line8"></a>//
<a name="line9"></a>// Unless required by applicable law or agreed to in writing, software
<a name="line10"></a>// distributed under the License is distributed on an &quot;AS-IS&quot; BASIS,
<a name="line11"></a>// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<a name="line12"></a>// See the License for the specific language governing permissions and
<a name="line13"></a>// limitations under the License.
<a name="line14"></a>
<a name="line15"></a>/**
<a name="line16"></a> * @fileoverview Provide definition of an observer. This is meant to
<a name="line17"></a> * be used with {@code goog.labs.observe.Observable}.
<a name="line18"></a> *
<a name="line19"></a> * This file also provides convenient functions to compare and create
<a name="line20"></a> * Observer objects.
<a name="line21"></a> *
<a name="line22"></a> */
<a name="line23"></a>
<a name="line24"></a>goog.provide(&#39;goog.labs.observe.Observer&#39;);
<a name="line25"></a>
<a name="line26"></a>
<a name="line27"></a>
<a name="line28"></a>/**
<a name="line29"></a> * A class implementing {@code Observer} may be informed of changes in
<a name="line30"></a> * observable object.
<a name="line31"></a> * @see {goog.labs.observe.Observable}
<a name="line32"></a> * @interface
<a name="line33"></a> */
<a name="line34"></a>goog.labs.observe.Observer = function() {};
<a name="line35"></a>
<a name="line36"></a>
<a name="line37"></a>/**
<a name="line38"></a> * Notifies the observer of changes to the observable object.
<a name="line39"></a> * @param {!goog.labs.observe.Notice} notice The notice object.
<a name="line40"></a> */
<a name="line41"></a>goog.labs.observe.Observer.prototype.notify;
<a name="line42"></a>
<a name="line43"></a>
<a name="line44"></a>/**
<a name="line45"></a> * Whether this observer is equal to the given observer.
<a name="line46"></a> * @param {!goog.labs.observe.Observer} observer The observer to compare with.
<a name="line47"></a> * @return {boolean} Whether the two observers are equal.
<a name="line48"></a> */
<a name="line49"></a>goog.labs.observe.Observer.prototype.equals;
<a name="line50"></a>
<a name="line51"></a>
<a name="line52"></a>/**
<a name="line53"></a> * @param {!goog.labs.observe.Observer} observer1 Observer to compare.
<a name="line54"></a> * @param {!goog.labs.observe.Observer} observer2 Observer to compare.
<a name="line55"></a> * @return {boolean} Whether observer1 and observer2 are equal, as
<a name="line56"></a> *     determined by the first observer1&#39;s {@code equals} method.
<a name="line57"></a> */
<a name="line58"></a>goog.labs.observe.Observer.equals = function(observer1, observer2) {
<a name="line59"></a>  return observer1 == observer2 || observer1.equals(observer2);
<a name="line60"></a>};
<a name="line61"></a>
<a name="line62"></a>
<a name="line63"></a>/**
<a name="line64"></a> * Creates an observer that calls the given function.
<a name="line65"></a> * @param {function(!goog.labs.observe.Notice)} fn Function to be converted.
<a name="line66"></a> * @param {!Object=} opt_scope Optional scope to execute the function.
<a name="line67"></a> * @return {!goog.labs.observe.Observer} An observer object.
<a name="line68"></a> */
<a name="line69"></a>goog.labs.observe.Observer.fromFunction = function(fn, opt_scope) {
<a name="line70"></a>  return new goog.labs.observe.Observer.FunctionObserver_(fn, opt_scope);
<a name="line71"></a>};
<a name="line72"></a>
<a name="line73"></a>
<a name="line74"></a>
<a name="line75"></a>/**
<a name="line76"></a> * An observer that calls the given function on {@code notify}.
<a name="line77"></a> * @param {function(!goog.labs.observe.Notice)} fn Function to delegate to.
<a name="line78"></a> * @param {!Object=} opt_scope Optional scope to execute the function.
<a name="line79"></a> * @constructor
<a name="line80"></a> * @implements {goog.labs.observe.Observer}
<a name="line81"></a> * @private
<a name="line82"></a> */
<a name="line83"></a>goog.labs.observe.Observer.FunctionObserver_ = function(fn, opt_scope) {
<a name="line84"></a>  this.fn_ = fn;
<a name="line85"></a>  this.scope_ = opt_scope;
<a name="line86"></a>};
<a name="line87"></a>
<a name="line88"></a>
<a name="line89"></a>/** @override */
<a name="line90"></a>goog.labs.observe.Observer.FunctionObserver_.prototype.notify = function(
<a name="line91"></a>    notice) {
<a name="line92"></a>  this.fn_.call(this.scope_, notice);
<a name="line93"></a>};
<a name="line94"></a>
<a name="line95"></a>
<a name="line96"></a>/** @override */
<a name="line97"></a>goog.labs.observe.Observer.FunctionObserver_.prototype.equals = function(
<a name="line98"></a>    observer) {
<a name="line99"></a>  return this.fn_ === observer.fn_ &amp;&amp; this.scope_ === observer.scope_;
<a name="line100"></a>};
</pre>


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